As population throughout the world increases, the disposition of human waste materials becomes an increasingly vexing problem. In many instances, federal, local and state agencies have resorted to stringent restrictions on the methods employed to dispose of such waste.
In less densely populated areas, where the per capita costs of sewage collection and treatment systems are prohibitive, on-site septic tank systems have represented the preferred method of human waste disposal for many years. Unfortunately, septic systems require precise soil characteristics for satisfactory performance. If soil percolation rates are too high, pathogenic and other contaminants can be carried into the water table and thereby present a public health hazard. If percolation rates are too low, septic tank effluents can bubble to the surface and present many undesirable consequences. Where the water table is high or is seasonably or variably high, there have been cases where septic tanks have floated out of ground in response to seasonal variations.
For the foregoing and other reasons, public agencies in growing numbers are prohibiting the use of septic tank systems unless rigid sub-surface conditions can be demonstrated to exist at the proposed building site. Because of these standards, there are many otherwise desirable building sites which cannot be utilized for construction unless public sewage systems are installed. This is an eventuality which may not occur. This results in otherwise desirable property lying idle in the face of tremendous needs for more housing and other building construction. These needs are oftentimes relieved by the selection of less desirable properties having better soil conditions.